BUILDING TECHNOLOGIE

March 26‐27, 20

ASRAC Pumps Working Group

Metric: Calculations and Standard Setting
2

 Review of PER metric and issues from last meeting

 Detailed examples for test procedure approach

• Calculation‐based method

- How to account for motor efficiency at part load and controls

• Testing‐based method

 Load point options

• Vote?

 Weighting options

• Vote?

 Denominator optionsOverview
3

Metric Applicability to Pump Configurations

Pump Configuration

Bare Pump Bare Pump + Driver Bare Pump + 

Metric Coverage

Bare Pump Does not include motor efficiency Does not d

losses 

Bare Pump +

Driver (w/ std. driver)

Does not d

losses 

Bare Pump +Driver +

Controls (w/ std. driver and controls) (w/ std. controls)

Pump Driver

Pump Control D
4

Covered Product Metric

Bare Pump

Efficiency

or Energy

Use

Driver

Efficiency

or Energy

Use

‘Pump’

Efficiency or

Energy Use

=
5

Possible MetricPump Energy Rating (PER): equally weighted average electric inpu

(P1) to the ‘pump’ measured (or calculated) at the driver input or, 

present, controls input, over a specified load profile (110%, 100%, 

50% of Best Efficiency Point (BEP) flow at nominal speed).

• For bare pump or pump+driver, a

part‐load by throttling through p

at rated speed.

• For pump+driver+controls, achie

load by reducing speed and corre

specified system curve shape.

PER = 0.25(P1BEP) + 0.25(P11.1BEP) + 0.25(P10.75 BEP) + 0.25(

Notes:Denominator could be included in metric

Rating points, load points, and weighting must be determined
6

Issues to Discuss• Metric

– Denominator

• Motor losses – bring examples to 3/26 meeting

– Full load only, different loss curves for different types of motors?

• Method to account for controls – bring examples to 3/26 meeting

– Testing for drive efficiency?

– Load Control Factor to account for different types: VSD, multi‐spe

ECMs?

• Load points (i) ‐ % of BEP flow

– 50%, 75%, 100%?

– 25%, 50%, 75%, 100%?

– 75%, 100%, 110%?

– 50%, 75%, 100%, 110%?

• Weighting (wi)

– Equal weighting? (w=0.25)

ࡲ࡯ࡸ ൌ ࡾࡱࡼ

૙૞.૙࣓

૙૞.૙ࡼ

࣓ ൅ ࢚࢒࢛ࢇࢌࢋࢊ,࢘࢕࢚࢕࢓η ࡼࡱ࡮ࡼ ࡼࡱ࡮࣓ ൅ ࢚࢒࢛ࢇࢌࢋࢊ,࢘࢕࢚࢕࢓η૞ ૠ.૙ࡼ ૞ૠ.૙࣓ ൅ ࢚࢒࢛ࢇࢌࢋࢊ,࢘࢕࢚࢕࢓η

࢕࢘ࢊ࢟ࡴࡼ
7

Metric Options• PER• MEI – describes pump only• EEI – describes impact of controls only

• gpm / kWh for electric pump/driver combinations• gpm / Btu for non‐electric pump/driver combinations

• kWh / gpm for electric pump/driver combinations• Btu / gpm for non‐electric pump/driver combinations

• kWh / (gallons or gpm * feet of head) for electric pump/driver

combinations

• Btu / (gallons or gpm * feet of head) for non‐electric pump/driv

combinations
8

 Calculation methods

• Bare shaft pump

• Bare pump sold with motor• Bare pump sold with motor and control (VFD)

 Test methods

• Bare pump sold with motor• Bare pump sold with motor and control

Sample Calculations of the PER Metric
9

Pump Used for Example CalculationsNote that this example is for a pump and motor combination. If th

group decides to include engine‐driven pumps in the scope of this

rulemaking, similar calculation methods will have to be developed 

separate physical test applied.

Pump Motor (if applicable) Type: OH1

Rated conditions:• Rated Flow: 900 GPM

• Rated Head: 160 ft

• Rated Speed: 1750 RPM

Power: 60 hpEfficiency: 95%No load speed (TestMotor): 1780 RPM [fourpole motor]
10

PER Calculation: Determining BEP Flow Rate (Q

• 7 points swept from shutoff to maximum flow rate, with flow rat

Head (ft), rotational speed (rpm), torque (in‐lbf) recorded in follo

• Hydraulic pump efficiency is calculated at each flow point

– Input power = (torque) x (speed)– Output power = (flow rate) x (head) x (specific weight of fluid)

– Efficiency = output power / input power

• BEP found by determining maximum of best fit curve

of efficiency with respect to flow rate

% of BEP

flow

Flow Rate

(GPM) Head (ft)

Speed

(RPM)

Torque

(lb‐in)

Hydraulic

Power

(hp)

Shaft input

power (hp) η

128 1200.59 141.51 1774.10 1977.14 41.76 55.65 7108 1012.80 157.91 1774.63 1782.87 39.31 50.20 78100 939.62 162.58 1774.80 1721.36 37.55 48.47 77

91 851.24 169.44 1775.86 1613.80 35.46 45.47 776 709.87 178.40 1775.85 1458.85 31.13 41.11 758 547.19 186.61 1777.84 1251.15 25.10 35.29 748 449.06 189.67 1778.80 1112.42 20.94 31.40 6
11

×

standardized motor

efficiency (and part load

curve?)

MOTOR

pump performan

from pump test 

speed

Bare Pump

×

standardized controls

performance

Controls

• Standard motor: AC Induction, NEMA Design B, open enclosure.

• HP used will be next HP above brake horsepower at 120% of BEP HP.

• Poles will be based on speed at which pump is being rated.

Issues• Standardized Motor Performance

• Standard full load motor efficiency for all points, based on Federal sta

• Develop standard motor part‐load curves.

• Standardized Controls Performance

• Assume 100% efficiency; or• Develop standard control efficiency, potential with part‐load curves.
12

Determining Bare Pump Performance• Determine brake hp at Q50%, Q75%, Q100% and Q110% flow rates

– Pump brake hp obtained from best fit curve of brake hp vs flow rate

Load Point Flow rate [GPM] Pump brake hp [HP]

Q110% 1034 50.65

Q100% 940 47.66

Q75% 705 40.16Q50% 470 32.66

૙૞.૙࣓ ࡲ࡯ࡸ ൌ ࡾࡱࡼ

૙૞.૙ࡼ

࢚࢒࢛ࢇࢌࢋࢊ,࢘࢕࢚࢕࢓η

૞ૠ.૙࣓ ൅

૞ૠ.૙ࡼ

࢚࢒࢛ࢇࢌࢋࢊ,࢘࢕࢚࢕࢓η

ࡼࡱ࡮࣓ ൅

ࡼࡱ࡮ࡼ

࢚࢒࢛ࢇࢌࢋࢊ,࢘࢕࢚࢕࢓η

࣓ ൅

࢖ࢎ	૞૟ .૙૞ ૞૛ .૙ ࡲ࡯ࡸ ൌ ࡾࡱࡼ

࢚࢒࢛ࢇࢌࢋࢊ,࢘࢕࢚࢕࢓η

࢖ࢎ	૟૟ .ૠ ૛૞ ૝.൅ ૙

࢚࢒࢛ࢇࢌࢋࢊ,࢘࢕࢚࢕࢓η

࢖ࢎ	૟૚ .૙૝ ૞૛ .૙ ൅

࢚࢒࢛ࢇࢌࢋࢊ,࢘࢕࢚࢕࢓η

.૙ ൅
13

Accounting for Motor Losses

• Full load motor efficiency (ηmotor,default) for the bare shaft pump PE

obtained from Table 3 in 10 CFR 431.25 (subpart B)

– Determine pump shaft hp at 120% of BEP flow = 1128 GPM = 53.65 hp ‐> 60 

– For a four pole motor with rated load of 60 hp, the full load efficiency

ηratedDOE = 93.6%

• To account for motor losses with decreased loading, one could ca

losses at each load point based on a load fraction:

– Calculate load fraction (brake hp at each load point

divided by rated motor load [60 hp])

• From load fraction and part load points obtained from brake hp d

the part‐load loss factors at each motor load point using an equat

– yi = 0.12xi3 + 0.18xi2 + 0.4xi +0.3

• Where yi is the loss factor at each load point (i), and xi is the load fraction for each 

ൌ ࢏࢞

࢏ࡼ

ሿ࢖ࢎሾࢋࢠ࢏ࡿ࢘࢕࢚࢕ࡹ

ൌ

࢏ࡼ

࢖ࢎ	૙૟
14

Accounting for Motor Losses

• Calculate the fractional load loss at each flow point using: ܮ ௜ൌ ܮ

– Where Li is the fractional load loss at each flow point in hp, Lfull,rated is the full 

determined in accordance with 10 CFR 431.25 (subpart B) in hp, and yi is the 

factor for each flow point

• Calculate the fractional input power as follows: ܲ௜௡௜ ൌ ܲ௜ ൅ ܮ௜

– Where Pi is the bare shaft input power in hp and the fractional load loss at ea

Lfull,rated is the full load losses determined in accordance with 10 CFR 431.25 (

– Calculate fractional input power as follows: Piin = Pi + Li

% BEP flow

Bare pump

shaft input

power (hp)

Load

fraction

(xi)

Part load loss

factor (yi)

Fractional load

loss (hp)

F

110 50.65 0.84 0.84 3.44 100 47.66 0.79 0.79 3.25 

75 40.16 0.70 0.68 2.81 

50 32.66 0.54 0.59 2.42 
15

Determining Bare Pump Performance ‐ Calcula

• Calculate PER by weighting each of the input power va

follows:

• Assume standardized load control factor of 1.

૙ ൅ ࢖ࢎ	૙ૢ .૙૞ ૞૛ .૙ ൅ ࢖ࢎ	ૠૢ . ૛૞ ૝૛. ൅ ૙࢖ࢎ	ૡ ૙. ૛૞ ૜૞. ૙ࡲ࡯ࡸ ൌ ࡾࡱࡼ

࢖ࢎ	૟ૠ . ૝૞ൌ ࡾࡱࡼ
16

Motor Losses Equation• Motor loss curves based on Motor Masters Database• Different load loss curves for ODP/TEFC and 2‐pole/4

motors

• Other options?

y = 0.12x3 + 0.18x2 + 0.4x + 0.3

0

0.20.40.60.8

1

1.2

0 0.5 1 1.5

Fraction of full load power loss

Fraction of full load power

ODP motors at 3600 RPM

CuMPo

Po
17

×

manufacturer motor

efficiency at full and part

load

MOTOR

Bare Pump + Motor

Ma

pai

wit

pump performance 

data from pump

test at rated speed

standardized

controls

performance

Controls ×

MOTOR PUMP

Ma

me

p

standardized

controls

performance

Controls ×

motor/drive performance data

BA
18

Determining Bare Pump + Motor Performance –Calculation Method

• Calculate PER using the same method as for the bare shaft pump 

– Incorporate the rated motor efficiency rather than DOE minim

• Assume 60 hp motor with ηmotor,meas = 95% (Lfull,rated = 3.16 hp) and 

before:

૙૞.૙࣓ ࡲ࡯ࡸ ൌ ࡾࡱࡼ

૙૞.૙ࡼ

࢙ࢇࢋ࢓,࢘࢕࢚࢕࢓η

૞ૠ.૙࣓ ൅

૞ૠ.૙ࡼ

࢙ࢇࢋ࢓,࢘࢕࢚࢕࢓η

ࡼࡱ࡮࣓ ൅

ࡼࡱ࡮ࡼ

࢙ࢇࢋ࢓,࢘࢕࢚࢕࢓η

࣓ ൅

૙ ൅ ࢖ࢎ	૞૚ .૙૞ ૞૛ .૙ ൅ ࢖ࢎ	૛૜ .૛૝ ૞૛ .૙ ൅ ࢖ࢎ	૜૞ .૝૜ ૞૛ .૙ ∗ ૚ ൌ ࡾࡱࡼ

࢖ࢎ	ૡ ૙. ૝૞ൌ ࡾࡱࡼ

% BEP flow

Bare pump

shaft input

power (hp)

Load

fraction

(xi)

Part load loss

factor (yi)

Fractional load

loss (hp)

F

110 50.65 0.84 0.84 2.65 100 47.66 0.79 0.79 2.50 

75 40.16 0.70 0.68 2.16 

50 32.66 0.54 0.59 1.86 
19

pump performance from pump test at

rated and reduced speed

×

motor/drive performance

data

BC

VFD MOTOR

Controls MOTOR PUMP

Bare Pump + Motor + Controls

Ma

pai

mo

Ma

me

p

co

×

manufacturer or default

motor efficiency

A MOTOR

Ma

pai

with 

m

de

pump performance

data from pump test

at rated speed

default controls

performance

Controls ×
20

• Instead of wire‐to‐water or full drive system testing, could apply 

calculation factor to account for energy savings from control to 

uncontrolled pump + motor:

• PER calculated for all three control options using :

– bare pump shaft input power at BEP flow,

– motor nameplate efficiency, and

– pump affinity laws

Determining Bare Pump + Motor + Controls Performan

૙૞.૙࣓ ࡲ࡯ࡸ ൌ ࡾࡱࡼ

૙૞.૙ࡼ

࢙ࢇࢋ࢓,࢘࢕࢚࢕࢓η

૞ૠ.૙࣓ ൅

૞ૠ.૙ࡼ

࢙ࢇࢋ࢓,࢘࢕࢚࢕࢓η

ࡼࡱ࡮࣓ ൅

ࡼࡱ࡮ࡼ

࢙ࢇࢋ࢓,࢘࢕࢚࢕࢓η

࣓ ൅
21

Control factor: Basis

 In this example, load control factor is defined as the ratio of PER 

controlled pump to the PER of an uncontrolled pump

• ܨܥܮ ൌ 	 ௉ாோ಴೚೙೟ೝ೚೗೗೐೏

௉ாோೆ೙೎೚೙೟ೝ೚೗೗೐೏

• Load control factor for the VFD provided in PER calculation examp

depending on load profile and weighting

 PER of pump+motor will be used to determine the LCF for each 

 Need to assume specific control options:

• Potential control options could include multi‐speed motors,

brushless DC (or ECM) motors and VFD controllers

 Use an assumed conservative system curve for all three options 

variations to determine the Load Control Factor

• Account for motor losses in conservative LCF

 Assumptions:

• Efficiency of control = 96%
22

Control factor: VFD• Calculate PER using flow points along system curve, 

than using flow points along one constant speed pum

(but no over‐speeding)

• The system curve is defined by

the following pump affinity laws:

• 2.8 power exponent based on ASHRAE data suggesti

system curves have a relationship between head and 

an exponent from 1.8 to 1.9

૚ࡽ૛ࡽ

ൌ

૚࢔૛࢔

૚ࡴ૛ࡴ

ൌ

૚࢔૛࢔

૚.ૡ

૚ࡼ૛ࡼ

ൌ

૚࢔૛࢔

૛.ૡ

Referenc

H

Q50% Q7

H100%
23

Control factor: VFD ‐ Calculations

• The flow at input power to the bare pump are available from th

pump performance:

• Using the pump affinity laws, the bare pump shaft input power 

BEP flow (660 GPM) is:

• Applied to all rating points yields the following:

ࡳ	૙૝ૢ ൌࡼࡱ࡮ࡽ															;ܘܐ	ૠ .ૠ ૝ൌ ࡼࡱ࡮ࡼ

૚ࡼ૛ࡼ

ൌ

૚࢔૛࢔

૜

ൌ

૚ࡽ૛ࡽ

૛.ૡ

૞ૠ.૙ࡼ

࢖ࢎ	૟૟ .ૠ૝

ൌ

ࡹࡼࡳ	૞૙ૠࡹࡼࡳ	૙૝ૢ

૛.ૡ

ࡼ૙.ૠ૞ ൌ ૝ૠ. ૟૟	࢖ࢎ

ࡹࡼࡳ	૞૙ૠࡹࡼࡳ	૙૝ૢ

૛.ૡ

࢖ࢎ	૙૜ .૚૛ ൌ

Load Point Flow (GPM) Bare pump input

power (hp)

Q110% 1034 53.56

QBEP 940 47.66

Q75% 705 21.30Q50% 470 6.84
24

Control factor: VFD ‐ Calculations

• Assuming the motor is a 95% efficient motor (as befo

drive is 96% efficient, the controlled PER (PERc) is the

• The Load Control Factor that would be applied to all p

ratio of the uncontrolled PER (bare pump + motor) to 

controlled PER:

∗૚ൌ ࢉࡾࡱࡼ

.૙ ൅ ࢖ࢎ	૞૚ .૙૞ ૞૛ .૙ ൅ ࢖ࢎ	ૠૡ . ૛૞ ૛૛. ൅ ૙࢖ࢎ	૝ૢ .ૠ ૛૞ .૙

૙. ૢ૟

࢖ࢎ	૞૚ .૞૜ ൌ ࢉࡾࡱࡼ

ࢉࡾࡱࡼ

ࡾࡱࡼ

ൌ

૜૞. ૚૞૝૞. ૙ૡ

ࡲ࡯ࡸ ൌ ૙. ૠૡ
25

Control factor: Two Speed Motor

• Based on bare pump input power at BEP,

nameplate motor efficiency, motor loss curves,and rated speeds (low and high speed):

– Assume for this calculation that low speed is 1⁄2 of

high speed

Load Point Rated Speed (RPM) Power (hp) % Moto

Q110% 1750 53.30 84

QBEP 1750 50.15 79

Q75% 1750 42.32 67Q50% 875 7.94 11% (

૚ࡼ૛ࡼ

ൌ

૚࢔૛࢔

૛.ૡ

ൌ

૚ࡽ૛ࡽ

૛.ૡ

࢖ࢎ	૞૚ .૙૞	ൌ૞૙ .૙ࡼ

ࡹࡼࡾ	૞ૡૠ

ࡹࡼࡾ	૙૞ૠ૚

૛.ૡ

	ൌ ૠ. ૢ૝
26

Control factor: Two Speed Motor ‐ Calculation

• Assuming the motor is a 95% efficient motor (as befo

controlled PER (PERc) is then:

• The Load Control Factor that would be applied to all p

ratio of the uncontrolled PER (bare pump + motor) to 

controlled PER:

૛ .૙ ൅ ࢖ࢎ	૞૚ .૙૞ ૞૛ .૙ ൅ ࢖ࢎ	૛૜ .૛૝ ૞૛ .૙ ൅ ࢖ࢎ	૝ૢ .ૠ ૛૞ . ૙ൌ ࢉࡾࡱࡼ

࢖ࢎ	૜૝ .ૡ ૜ൌ ࢉࡾࡱࡼ

ࢉࡾࡱࡼ

ࡾࡱࡼ

ൌ

૜ૡ. ૝૜૝૞. ૙ૡ

ࡲ࡯ࡸ ൌ ૙. ૡ૞
27

Two Speed Motor Issues• Assumes lower speed is initiated

at ~60% loading

• For other than 2‐1 windings, could calculate P0.50 bas

actual low speed ratio ௡మ௡భ for motor to determine L

each motor up to 2‐1

– A conservative assumption could be P0.50=P(Q@n2), which 

curve

Motor Loading vs

55 hp 60 hp 

59.4% 54.4% 73.0% 66.9% 86.6% 79.4% 92.1% 84.4% 
28

Control factor: Issues• Issues:

– Other control options to be considered?

• Desirable to make technology neutral?

– Not possible to distinguish similar control options

– Account for efficiency of control?

• Default efficiency value should use a conservative estimate

• Allow for differentiation based on improved efficiency in cont
29

PER Calculation Comparison Summary• PER accounts for savings from control and from more 

motor

Equipment Configuration PER

Bare Pump 45.76Pump + 95% Eff. Motor 45.08

Pump + Motor + VSD 35.15

Pump + 2‐speed Motor 38.43
30

Bare Pump + Motor – Test Method• Referred to as “string test” in HI 14.6

– Test similar to bare shaft test procedure,

except motor input power (Pin,i) is measured

directly

• If motor efficiency changes significantly from rated v

tested PER will vary from calculated value

MOTOR PUMP

Manu

measu

pum

c

standardized controls

performance

Controls ×

Pump+moto

data from 

rated 

ࡼࡱ࡮,࢔࢏ࡼ ࡼࡱ࡮࣓ ൅ ૞ૠ.૙,࢔࢏ࡼ ૞ૠ.૙࣓ ൅ ૙૞.૙,࢔࢏ࡼ ૙૞.૙࣓ ࡲ࡯ࡸ ൌ ࡾࡱࡼ
31

pump performance from pump test at

rated and reduced speed

×

motor/drive performance

data

BC

VFD MOTOR

Controls MOTOR PUMP

Bare Pump + Motor + Controls

Ma

pai

mo

Ma

me

p

co

×

manufacturer or default

motor efficiency

A MOTOR

Ma

pai

with 

m

de

pump performance

data from pump test

at rated speed

default controls

performance

Controls ×
32

 Calculation is similar to pump + motor approach, but use comb

efficiency of motor + drive as determined by AHRI 1210:

 Drive system efficiency determined through interpolation of AH

tested points:

Determining Bare Pump + Motor + Controls PerformanAHRI 1210

Speed/

Torque Points

16% 25% 56% 

40% 85% 50% 91% 75% 93% 

100% 

૙૞.૙࣓ ࡲ࡯ࡸ ൌ ࡾࡱࡼ

૙૞.૙ࡼ

࢙ࢇࢋ࢓,ࢋ࢜࢏࢘ࢊη

૞ૠ.૙࣓ ൅

૞ૠ.૙ࡼ

࢙ࢇࢋ࢓,ࢋ࢜࢏࢘ࢊη

ࡼࡱ࡮࣓ ൅

ࡼࡱ࡮ࡼ

࢙ࢇࢋ࢓,ࢋ࢜࢏࢘ࢊη

૚࣓ ൅
33

Determining Bare Pump + Motor + Controls PerformAHRI 1210 Linearly interpolate points from AHRI to pump load p

 For example for P0.75 and assuming a 60 hp motor/VFD with 

load speed of 1800 RPM:

Load Point Rated Speed (RPM) Torque (lb‐in) Bare Pum

Powe

Q110% 1750 1783 50

QBEP 1750 1721 47

Q75% 1312.5 1459 21

Q50% 875 1112 6.8

Speed/

Torque Points 352 lb‐in 550 lb‐in 1232 lb‐in 2

720 RPM 85% 900 RPM 91% 

1350 RPM 93% 

1800 RPM 
34

Interpolating AHRI 1210 Drive Efficiencies• Select the speed/torque point closest to the P0.75 loa

• For the speed adjustment:

– Select the higher and lower speed/torque points:

ηࢋ࢜࢏࢘ࢊ,૙.ૠ૞ ൌ

%૙૞࢔,ࡵࡾࡴ࡭,ࢋ࢜࢏࢘ࢊη	െ %૞ૠ࢔,ࡵࡾࡴ࡭,ࢋ࢜࢏࢘ࢊη

࡭࢔െ૞ૠ.૙࢔ሺ %૞૙࢔,ࡵࡾࡴ࡭࢔ െ %૞ૠ࢔,ࡵࡾࡴ࡭࢔

%૟૞࣎,ࡵࡾࡴ࡭,ࢋ࢜࢏࢘ࢊη	െ %૚૙૙࣎,ࡵࡾࡴ࡭,ࢋ࢜࢏࢘ࢊη

૞

࢔,ࡵࡾࡴ࡭࣎ െ૞ ૠ.૙࣎ሺ %૞૟࣎,ࡵࡾࡴ࡭࣎ െ %૚૙૙࣎,ࡵࡾࡴ࡭࣎

%૞ૠ࢔,ࡵࡾࡴ࡭,ࢋ࢜࢏࢘ࢊη

ηࢋ࢜࢏࢘ࢊ,૙.ૠ૞ ൌ

ૢ૜% െ ૢ૚%

૚ૡ૙૙ െ ૚૜૞૙ ૚૜૚૛. ૞ െ ૚૜૞૙ ൅

ૢૡ% െ ૢ૜%

૛૛૙૙ െ ૚૛૜૛ ૚૝૞ૢ െ ૚૛૜૛ ൅ ૢ૜%

ൌ ૢ૝%	
35

Interpolating AHRI 1210 Drive Efficiencies• Applying this for both speed and torque and for all lo

• Note reduced speed pump input power data is appli

– Could be physically tested or assumed using pump affinity 

൅ 

࢖ࢎ	૞૝ .૝૛ ૞૛ .૙ ൅ ࢖ࢎ	ૡ ૚. ૛૞ ૞૚. ൅ ૙ૢ ૜. ૛૞ ૞૝. ૙ൌ ࡾࡱࡼ

࢖ࢎ	૝૙ .૝૜ ൌ ࡾࡱࡼ
36

• Can be harmonized with HI 40.6 method of test to determ

for extended products

– 40.6 focuses on pump efficiency determination by measuring 

hp and pump hydraulic power output

– AHRI 1210 can be used to rate the part load efficiency of comb

system

• Proposed speed/torque loading is in line with system cur

proposed in PER calculation method

– Speed torque load profile is quadratic: 50% of synchronous sp

corresponds to 25% full load torque

• Tolerances are more stringent than HI 40.6 on both input 

output side

• Issues:

– AHRI 1210 may not be ready in time

– How to apply to other drive types (e.g. engines)?

– If standard is set using full load efficiency for motors, there ma

inherent penalty to this method (although still would come ou

AHRI 1210: Details & Issues
37

• Also known as “string” test, addressed in appendices as an non

mandatory method in HI 14.6

• Potential measurement method:

– Measure input power to VFD terminals using same protocol as AHRI 1210 

(need to consider HI 11.6 for submersible pumps in order to address unde

electrical power measurements)

– Measure output hydraulic power using HI 40.6

• Due to nature of VFD control method, harmonics affect efficien

system such that drive system efficiency is not same as produc

individual motor and VFD efficiencies

• Could be applied to some pump types (e.g. submersibles and c

only

Determining Bare Pump + Motor (+ Controls) PerformWire‐to‐Water Testing

Controls MOTOR PUMP

Ma

me

p

co
38

PER Comparison Summary Using Test Methods• Testing:• Calculation:

Equipment Configuration PER

Pump + 95% Eff. Motor 44.95

Pump + Motor + VSD – AHRI 1210 34.04

Pump + Motor + VSD – Wire‐to‐Water 33.83

Equipment Configuration PER

Bare Pump 45.76Pump + 95% Eff. Motor 45.08

Pump + Motor + VSD 35.15

Pump + 2‐speed Motor 38.43
39

Applicable Test Methods• Should manufacturers have the option to test or sho

calculation method be required?

• Is physical testing more appropriate for some equipm

classes while a calculation method is more appropria

others?

Test Method Pros ConsCalculationMethod

Repeatable;Less burdensome

Does not differentiat

controls performancAssumptions regardi

motor/controls effici

changing load requir

Decreased accuracy

Physical TestMethod

Accurate;Differentiates performance of

different motor/controlsequipment at full and part load

Burdensome;AHRI 1210 test data 
40

 Options for the PER metric load points could include:

• 50%, 75%, 100%, and 110% of BEP flow

• 75%, 100%, and 110% of BEP flow

• Others?

 25% of BEP flow

• Some pumps may have difficulty or not be able to operate at the 

point without controls (i.e. with throttling)

• Exaggerates improved performance with controls due to low load

 110% of BEP flow

• This point is part of the EU “house of efficiency,” designed to enco

broad efficiency curve

PER Load Point Choice

૙૞.૙࣓ ࡲ࡯ࡸ ൌ ࡾࡱࡼ

૙૞.૙ࡼ

࢚࢒࢛ࢇࢌࢋࢊ,࢘࢕࢚࢕࢓η

૞ૠ.૙࣓ ൅

૞ૠ.૙ࡼ

࢚࢒࢛ࢇࢌࢋࢊ,࢘࢕࢚࢕࢓η

ࡼࡱ࡮࣓ ൅

ࡼࡱ࡮ࡼ

࢚࢒࢛ࢇࢌࢋࢊ,࢘࢕࢚࢕࢓η

࣓ ൅
41

• Load points assuming equal weighting:• Choice of load points does not impact ranking, only r

magnitude

– Less lower load points de‐emphasizes impact of controls

Impact of Different Load Points

Load profile

Pump Energy Rating (PER) 

Bare

pump

Pump &

Motor

Contro

VFD 

25%, 50%, 75%, 100% of BEP flow 39.05 38.44 21.97 

50%, 75%, 100%, 110% of BEP flow 45.76 45.08 35.15 

Constant load at 25% 27.25 26.77 2.76 

Constant load at 100% 50.90 50.15 52.23 
42

Normal Load Curve• Assume normal curve stretches from 0% of BEP flow 

of BEP flow

• Could select specific values (red diamonds) or bin we

≤50%, ≤75%, ≤100%, and <100% (green boxes).

0

0.005

0.01

0.015

0.02

0.025

0 10 20 30 40 50 60 70 80 90 100 110 

Weight Value

% of BEP Flow
43

• Assume load points of 50%, 75%, 100% and 110% of Impact of Different Weightings

Load profile

Pump Energy Rating (PER) 

Bare

pump

Pump &

Motor

Contro

VFD 

Equal weighting 45.76 45.08 35.15 

Normal Load Curve (Discrete) 40.00 39.38 19.52 

Normal Load Curve (Bins) 42.39 41.75 25.76 

0

0.10.20.30.40.50.6

50 75 100 110

Weight Value

% of BEP Flow

NormaliNormaliEqual W
44

PER Options

No Denominator Denominator

Form Weighted average of

pump input power at

several load points

Weighted input of pump in

several load points normal

hydraulic output power, a 

pump efficiency, or other v

Units kW, Btu, or HP Dimensionless*Standard Strong function of flow

and specific speed

Weak function of flow and 

speed

Pros Representative of the

energy consumption of

that pump in the field

More comparable across pdifferent sizes/specific spe

Similar to EEI approach in 

Cons Not comparable across

pumps of different

flows/specific speeds

No reference pump efficie

difficult to set; other deno

options may not be logical 

next slide)

*May vary based on denominator chosen
45

Denominator Options

Denominator Pros ConsPower consumptionof same pump in an

uncontrolled system

N/A

This value give

efficiency of th

with equivalenperformance a

efficiencies at 

same rated val

Reference shaft

power for minimally

compliant bare pumpwith minimally

compliant motor

Results in value between 0

and 1.Clearly indicates performance

of a pump relative to a

baseline.

Inherently requ

minimally com

MEI). May ovethe baseline ef

pumps.

Market average shaft

power with

minimally compliantor market average

motor

Indicates performance of a

pump relative to the market.

Locks in the m

performance o

market at a giv

Doesn’t limit m

0 and 1.

Tested pump’s

hydraulic power at

BEP

Accounts for differences in

pump efficiencies betweenmodels.Has similar rated values for

pumps of different sizes

Lower PER ratibecause lower is inherently le
46

Possible Denominator Scaling Options• To determine the normalized PER using the various denominat

scale the PER without a denominator as follows:

ܲܧܴே௢௥௠ ൌ

ܲܧܴை௅஽	ሺ݄݌ሻ

ሻ݌݄ሺ	ܯܱܰܧܦ

• For 50%, 75%, 100%, and 110% of BEP flow as load points and 

weighting:

Denominator

Scaling Options Value (hp)

Pump energy rating (PER

Bare shaft

pump

Pump &

motor Pump, 

Hydraulic power 37.6 1.219 1.200 

Shaft Power 47.6 0.960 0.946 

Minimally

Compliant

(MEI10)

64.4 0.711 0.710 

Market Average

(MEI50) 59.3 0.7713 0.7712